A structure of an existing folding bed includes a bed frame having a tilt angle and a bed surface fixed on the bed frame. After the bed frame is unfolded, the bed surface is stretched tightly over the surface of the bed frame, thereby forming the folding bed. In a camp bed disclosed by the Chinese Invention Patent No. CN2543429Y, front and rear vertical surfaces of a bed frame thereof are separately formed by a group of slanting poles pivotally connected crosswise; left and right vertical surfaces of the bed frame are separately formed by two groups of slanting poles pivotally connected crosswise; end portions of the slanting poles of the bed frame are pivotally connected to upper and lower foot plates separately; and meanwhile, a vertical pole is further disposed in a matching manner between groups of slanting poles pivotally connected crosswise on the left and right vertical surfaces of the bed frame; in addition, longitudinal poles matching the bed surface are disposed in a matching manner at upper ends of the slanting poles on the left and right vertical surfaces of the bed frame; the left and right longitudinal poles are each formed by pivotally connecting four pole pieces sequentially to upper ends of the slanting poles and the vertical poles. Such a structure can implement convenient folding and unfolding of the bed body.
However, the folding bed of this structure has the following disadvantages:
1. Because the left and right longitudinal poles of the bed frame are each formed by four pole pieces, a pivotal connection part of pole pieces definitely exists in the middle part of the bed body; moreover, because a pivotal connection position of two adjacent pole pieces in the middle part of the bed body is set at the upper foot plate of the slanting pole, when a force is applied on the bed frame, a relatively large torsion is produced at the pivotal connection position in the middle part of the bed body, which easily causes a problem that the pivotal connection position is easy to be fractured, leading to safety hazards in use of the bed frame.
2.
The left and right longitudinal poles of the bed frame are each formed by four pole pieces; therefore, the longitudinal poles have more pivotal connection points, which is also a cause of the unstable support of the bed frame, and further affects use comfort of the bed frame.